Because it's the most fun I can have with my clothes on; I can play with anyone and everyone, regardless of sex, age, or ability; we can play one-on-one or in groups -- the more, the merrier; playing by myself isn't frowned on, though it's actually more difficult; it's OK for people to stop and just watch; "Please" and "Thank you" are an integral part of practice; even when it hurts, it's good.